CN110044731B - Non-uniform normal load structural surface direct shear test method and auxiliary loading device - Google Patents
Non-uniform normal load structural surface direct shear test method and auxiliary loading device Download PDFInfo
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- 238000007660 shear property test Methods 0.000 title claims abstract description 10
- 238000003825 pressing Methods 0.000 claims abstract description 56
- 230000003746 surface roughness Effects 0.000 claims abstract description 7
- 238000000034 method Methods 0.000 claims description 10
- 238000012360 testing method Methods 0.000 claims description 10
- 230000000149 penetrating effect Effects 0.000 claims description 6
- 238000012163 sequencing technique Methods 0.000 claims description 6
- 238000010008 shearing Methods 0.000 claims description 3
- 239000011435 rock Substances 0.000 description 11
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 230000002787 reinforcement Effects 0.000 description 1
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- G—PHYSICS
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- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/24—Investigating strength properties of solid materials by application of mechanical stress by applying steady shearing forces
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
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Abstract
The invention discloses a direct shear test method and an auxiliary loading device for a non-uniformly distributed normal load structural surfaceiDetermining a normal load value sigma required to be applied by loading equipment, measuring a joint surface roughness coefficient (JRC), a joint uniaxial compressive strength value (JCS) and a friction angle of a joint surface, determining a joint shear strength empirical (JRC-JCS) model formula, and finally integrating the JRC-JCS model in a normal stress interval on the whole joint surface to obtain the structural surface shear strength under the action of non-uniform normal loads. The auxiliary loading device converts normal loads into non-uniform loads by utilizing the principle that rigid pressing strips with different rigidity are stressed differently when deformed identically.
Description
Technical Field
The invention belongs to the field of structural plane shear tests in rock mechanics, and particularly relates to a non-uniform normal load structural plane direct shear test method and an auxiliary loading device.
Background
In engineering construction activities such as side slopes, water conservancy projects, tunnels and the like, rock masses with structural characteristics formed by cutting structural surfaces such as joints, cracks and the like are frequently encountered, and belong to heterogeneous materials, and the mechanical stability of the rock masses is controlled by the structural surfaces. The deterioration of the shear resistance of the rock mass structural plane often leads to engineering failures, such as slope slip, which endangers the safety of engineering equipment and personnel. Therefore, the judgment and the reinforcement of the rock mass structural plane are extremely important.
Instability of the rock mass structural plane is mainly manifested as sliding failure along the contact interface, and the stability of the rock mass structural plane depends on the shear resistance on the structural plane. The factors influencing the shear resistance of the structural surface in the rock mass mainly include overlying load and roughness. Due to the difference of the occurrence conditions, the thickness of the coating on the structural surface is often non-uniformly distributed. Therefore, the structure surface is subjected to non-uniform load, and further the stress distribution of the rough body on the contact surface is influenced by the uneven degree and the distribution form of the overlying load.
At present, the research on the structural plane is carried out under the condition of uniformly distributed normal load, but the research on the non-uniformly distributed load condition is not related. In order to carry out research on the problems of estimation of the peak shear strength of a structural plane under non-uniform load and the like, a method and a device are provided for realizing the loading of non-uniformly distributed normal force. In addition, aiming at the rough joint surface under the non-uniform load, the shear strength of the structural surface presents obvious nonlinear characteristics, so that different shear strengths are provided at the positions of the structural surface corresponding to different normal stress distribution forms on the structural surface, and the presented integral shear resistance is different, so that the calculation can not be carried out by using the simple linear superposition of the traditional linear shear strength model.
Disclosure of Invention
The invention aims to provide a simple and feasible structural surface direct shear test method and an auxiliary loading device for the same, which are suitable for non-uniform normal load.
The invention provides a direct shear test method for a non-uniform normal load structural surface, which comprises the following steps:
step one, determining a distribution form of a load;
determining a rigidity distribution sequence of the rigid pressing strips for loading according to the distribution form of the load;
thirdly, selecting rigid pressing strips with different rigidities according to rigidity distribution, and sequencing the rigid pressing strips according to a rigidity distribution sequence;
step four, normal load sigma borne by each rigid pressing strip after sequencingiDetermining a normal load value sigma required to be applied by loading equipment;
measuring the roughness coefficient (JRC) of the joint surface, the uniaxial compressive strength value (JCS) of the joint and the friction angle of the joint surface, and determining a joint shear strength empirical (JRC-JCS) model formula;
and step six, integrating the JRC-JCS model in a normal stress interval on the whole joint surface to obtain the shearing strength of the structural surface under the action of the non-uniform normal load.
In one specific embodiment, in the second step, the relationship between the stiffness of the rigid batten and the borne load is as follows:
wherein n is the number of rigid battens, σ1、σ2、σ3...σnThe load values, k, borne by different rigid battens determined according to the load distribution in the step one1、k2、k3...knThe rigidity values of different rigid pressing strips.
In order to avoid yielding of the rigid pressing strip in the loading process, in the second step, when the rigid pressing strip is selected, the compressive strength of the rigid pressing strip is not less than twice of the required bearing load.
Preferably, in the third step, the rigid pressing strips are rectangular parallelepiped strips, the roughness is not more than Ra0.40, the size error is not more than 1% of the minimum edge, and the rigid pressing strips are sequentially arranged from large rigidity to small rigidity.
In the fourth step, the normal load value sigma required to be applied by the loading equipment and the normal load sigma borne by each rigid pressing stripiThe relationship between them is:
in the fifth step, the expression of the JRC-JCS model is as follows:
wherein tau is shear stress, sigma is normal stress, JRC is joint surface roughness coefficient, sigmacFor uniaxial compressive strength of joint surfaces, phibIs the joint face friction angle.
The invention also provides an auxiliary loading device for the non-uniform normal load structural surface direct shear test method, which comprises a loading frame and a rigid pressing strip, wherein the loading frame is a rectangular frame and comprises a pair of clamping plates and a pair of side plates; the clamping plates are sleeved on the side plates, and the relative positions of the two clamping plates are adjustable; the rigid pressing strips are cuboid rigid pressing strips, and the rigid pressing strips are uniformly distributed between the two side plates in parallel and are clamped through clamping plates.
In a specific embodiment, two ends of the splint in the length direction are provided with strip-shaped grooves, and through holes are formed outside the strip-shaped grooves; a row of positioning holes are formed in the side plates along the length direction of the plates; the clamping plates are sleeved at the two ends of the side plates through strip-shaped grooves and are positioned through positioning pins penetrating through the positioning holes, and the pair of clamping plates are locked through screws penetrating through the through holes and matched with nuts.
When the invention is used for testing, firstly the distribution form of the load is determined, secondly the rigidity distribution sequence of the rigid pressing strips for loading is determined according to the distribution form of the load, then the rigid pressing strips with different rigidity are selected according to the rigidity distribution, then all the rigid pressing strips are sequenced according to the rigidity distribution sequence, and then the normal load sigma borne by all the rigid pressing strips after sequencing is used foriDetermining a normal load value sigma required to be applied by loading equipment, measuring a joint surface roughness coefficient (JRC), a joint uniaxial compressive strength value (JCS) and a friction angle of a joint surface, determining a joint shear strength empirical (JRC-JCS) model formula, and finally integrating the JRC-JCS model in a normal stress interval on the whole joint surface to obtain the structural surface shear strength under the action of non-uniform normal loads.
Drawings
Fig. 1 is a simplified model and discretization of a trapezoidal normal load distribution according to a preferred embodiment of the invention, expressed as σ -x +3(0 < x < 2).
Fig. 2 is a simplified model of the trapezoidal normal load distribution of this example with the expression σ ═ -1.2x +3.2(0 < x < 2).
Fig. 3 is a simplified model of the trapezoidal normal load distribution of the present embodiment with the expression σ ═ 2(0 < x < 2).
Fig. 4 is a front view schematically illustrating the auxiliary loading device in the preferred embodiment.
Fig. 5 is an enlarged side view of fig. 4. (rigid hold-down strip not shown)
Fig. 6 is an enlarged top view of fig. 4.
Detailed Description
The non-uniform normal load structural plane direct shear test method provided by the embodiment is implemented specifically by the following steps:
determining a load in a specific distribution form, and approximately processing the load into a discrete load; as shown in fig. 1, the distribution shown by the straight line is dispersed into loads shown by respective points, wherein the loads are represented by σ ═ x +3(0 < x < 2), and are 2.87MPa, 262MPa.. 1.37MPa, and 1.12MPa in this order.
Determining a rigidity distribution sequence of the rigid pressing strips for loading according to the distribution form of the load; the relationship between the rigidity of the rigid pressing bar and the borne load is as follows:
and if the load is determined in the step one, the rigidity ratio of the different rigid pressing strips is 2.87:2.62:2.37.
Thirdly, selecting rigid pressing strips with different rigidities according to rigidity distribution, and sequencing the rigid pressing strips according to a rigidity distribution sequence; and (2) preparing rigid pressing strips which accord with the rigidity ratio determined in the step two, wherein the number of the rigid pressing strips is integral multiple of discrete load (integral multiple of 8), simultaneously ensuring that the compressive strength of the rigid pressing strips is at least twice of the load value borne by the rigid pressing strips, avoiding yielding in the loading process and influencing the next use, and paying attention to that the geometric error of each edge is not more than 1% of the minimum edge during the rigid pressing strip processing, polishing the rigid pressing strips to ensure that the pressing planes of the rigid pressing strips are smooth, and then sequentially arranging the rigid pressing strips with different rigidity from left to right according to the sequence of the rigidity from large to small.
Step four, determining a normal load value sigma required to be applied by the loading equipment according to the normal load sigma i borne by each sorted rigid pressing strip;
according to the formula
Determining the normal loading value of the testing machine as follows: 2.875+2.625+. +1.375+1.125)/8 ═ 2 MPa; namely, the normal load of the testing machine is loaded to 2MPa at the moment, so that the trapezoidal non-uniform normal load determined in the step 1 in the figure 1 can be realized.
Step five, measuring the roughness coefficient (JRC) of the joint surface, the uniaxial compressive strength value (JCS) of the joint and the friction angle of the joint surface, determining the joint shear strength experience (JRC-JCS),
the model formula is as follows:
wherein tau is shear stress, sigma is normal stress, JRC is joint surface roughness coefficient, sigmacFor uniaxial compressive strength of joint surfaces, phibIs the joint face friction angle; the literature "Tang ZC, Wong LNY. New Criterion for Evaluating the Peak sheath Strength of Rock Joints Underfriendly differential controls states. Rock Mechanics and Rock engineering.2016 is adopted; 49: 1191-: the joint length L was 2m, the width B was 1m, the joint wall uniaxial compressive strength (JCS) was 27.5MPa, the joint surface roughness coefficient (JRC) was measured as 16.5, and the friction angle was 35 °; the cohesive force is 0.82MPa and the friction angle is 41.51 degrees when the adhesive is described by a molar-coulomb (M-C) model; for this joint, its JRC-JCS nonlinear shear strength is expressed as:
integrating the JRC-JCS model in a normal stress interval on the whole joint surface to obtain the shearing strength of the structural surface under the action of non-uniform normal load; here, the non-uniform load in the distribution form shown in fig. 1 is written as an algebraic expression: sigma is-x +3 (x is more than 0 and less than 2),
then JRC-JCS can be obtained:
the above procedure was repeated, and the shear resistance of the JRC-JCS model was calculated to be 5.402MPa for the load represented in fig. 2 in the form of a distribution with σ ═ -1.2x +3.2(0 < x < 2).
The above steps were repeated, and the shear resistance of the JRC-JCS model was calculated to be 5.462MPa for the load represented in fig. 3 in the form of a distribution whose expression σ ═ 2(0 < x < 2).
In order to verify the applicability of the JRC-JCS model, the shear strength of the structural plane under the non-uniform normal load is calculated for the loads in the three distribution modes by adopting the existing M-C model.
According to the document 1, the M-C model can be described as: τ is 0.82+0.885 σ;
namely for the M-C model:
the load under the three distribution forms is 5.180 MPa.
The results obtained for both models are compared in the following table:
| normal load distribution pattern | FIG. 1 is a schematic view of the form | FIG. 2 form | FIG. 3 form |
| JRC-JCS/MPa | 5.421 | 5.402 | 5.462 |
| M-C/MPa | 5.180 | 5.180 | 5.180 |
It can be seen that: for non-uniform loads with different forms and sizes, the results obtained by using the M-C model are the same, which also indicates the inapplicability of the M-C to the calculation of the shear strength of the structural surface under the non-uniform normal load; and the JRC-JCS model is utilized to simultaneously consider the influences of the non-uniform load and the structural surface roughness, provide a relatively excellent solution, and can be well suitable for the test of the non-uniform load.
As shown in fig. 4-6, the present embodiment further discloses an auxiliary loading device suitable for the above test, and the auxiliary loading device includes a loading frame 1 and a rigid pressing bar 2.
The loading frame 1 is a rectangular frame and comprises a pair of clamping plates 11 and a pair of side plates 12; the two ends of the clamping plate in the length direction are respectively provided with a strip-shaped groove, a through hole is arranged outside the strip-shaped groove, and a row of positioning holes are formed in the side plate 12 in the plate length direction; the clamping plates are sleeved at the two ends of the side plates by strip-shaped grooves and are positioned by positioning pins penetrating through the positioning holes, and the pair of clamping plates are locked by a screw rod 13 penetrating through the through hole and a nut; all the rigid pressing strips 2 are uniformly distributed between the two side plates in parallel and are clamped by the clamping plates.
The auxiliary loading device converts the applied normal load into the non-uniform load by utilizing the principle that the rigid pressing strips with different rigidity bear different forces under the same deformation condition, thereby realizing the normal non-uniform loading.
The invention overcomes the inapplicability of the traditional Moore-Coulomb (M-C) shear strength model to the calculation of the rough joint shear strength under the non-uniform normal load, simultaneously considers the influences of the joint morphology parameters and the non-uniform normal load, provides the auxiliary loading device of the structural surface shear strength under the action of the non-uniform load, and the auxiliary loading device has simple structure, is easy to process and operate, and the method for calculating the structural surface shear strength is easy to understand and convenient to use.
Claims (5)
1. A direct shear test method for a non-uniform normal load structural surface is characterized in that an auxiliary loading device is adopted to apply non-uniform load to the test;
the auxiliary loading device comprises a loading frame and a plurality of rigid pressing strips, wherein the loading frame is a rectangular frame and comprises a pair of clamping plates and a pair of side plates; the clamping plates are sleeved on the side plates, and the relative positions of the two clamping plates are adjustable; the rigid pressing strips are cuboid rigid pressing strips, and the rigid pressing strips are uniformly distributed between the two side plates in parallel and are clamped through clamping plates;
the method comprises the following steps:
step one, determining a distribution form of a load;
determining a rigidity distribution sequence of the rigid pressing strips for loading according to the distribution form of the load;
thirdly, selecting rigid pressing strips with different rigidities according to rigidity distribution, and sequencing the rigid pressing strips according to a rigidity distribution sequence;
step four, normal load sigma borne by each rigid pressing strip after sequencingiDetermining normal load values sigma applied to the upper ends of all rigid pressing strips by loading equipment, wherein the rigid pressing strips with different rigidities are stressed differently under the same deformation, so that the normal load applied by the loading equipment is converted into normal non-uniform load loading on a sample through each rigid pressing strip;
measuring the roughness coefficient JRC of the joint surface, the uniaxial compressive strength value JCS of the joint and the friction angle of the joint surface, and determining an empirical JRC-JCS model formula of the joint shear strength;
step six, integrating the JRC-JCS model in a normal stress interval on the whole joint surface to obtain the shearing strength of the structural surface under the action of non-uniform normal load;
in the second step, the relationship between the rigidity of the rigid pressing strip and the borne load is as follows:
wherein n is the number of rigid battens, σ1、σ2、σ3...σnThe load values, k, borne by different rigid battens determined according to the load distribution in the step one1、k2、k3...knThe rigidity values of different rigidity pressing strips;
in the fourth step, the normal load value sigma required to be applied by the loading equipment and the normal load sigma borne by each rigid pressing stripiThe relationship between them is:
2. the method for testing the structural plane of non-uniform normal load according to claim 1, wherein in the second step, when the rigid pressing bar is selected, the compressive strength of the rigid pressing bar is not less than twice of the required bearing load.
3. The method for the direct shear test of the structural surface with the nonuniform normal load according to claim 1, wherein in the third step, the rigid pressing strips are rectangular parallelepiped strips, the roughness is not more than Ra0.40, the size error is not more than 1% of the minimum edge, and the rigid pressing strips are arranged in sequence from the rigidity to the rigidity.
4. The method for the direct shear test of the non-uniform normal load structural surface as claimed in claim 1, wherein in the step five, the expression of the JRC-JCS model is as follows:
where τ is the shear stress and σ is the normal stressForce, JRC is the joint surface roughness coefficient, σcFor uniaxial compressive strength of joint surfaces, phibIs the joint face friction angle.
5. The non-uniform normal load structural surface direct shear test method of claim 1, characterized in that: the two ends of the splint in the length direction are provided with strip-shaped grooves, and through holes are formed outside the strip-shaped grooves; a row of positioning holes are formed in the side plates along the length direction of the plates; the clamping plates are sleeved at the two ends of the side plates through strip-shaped grooves and are positioned through positioning pins penetrating through the positioning holes, and the pair of clamping plates are locked through screws penetrating through the through holes and matched with nuts.
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| CN110864968B (en) * | 2019-11-27 | 2020-11-20 | 山东科技大学 | Stress gradient loading test device and method for accurately determining loading energy |
| CN111999179B (en) * | 2020-07-16 | 2024-05-14 | 青岛理工大学 | Device and method for manufacturing rock joints with different roughness |
| CN114486996B (en) * | 2022-01-27 | 2023-11-03 | 福建工程学院 | Intelligent control rock thermal expansion tester and application method thereof |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1815184A (en) * | 2006-02-24 | 2006-08-09 | 浙江建设职业技术学院 | Non-homogenous structural shear-strength sampling method |
| CN201765075U (en) * | 2010-09-09 | 2011-03-16 | 中国长江三峡集团公司 | Measuring device capable of measuring partial stress state of shearing surface |
| CN203981499U (en) * | 2014-05-16 | 2014-12-03 | 山东科技大学 | The non-uniform charger of a kind of large scale coal body |
| CN105466790A (en) * | 2015-11-10 | 2016-04-06 | 内蒙古科技大学 | Evaluation method of shear strength of rock structural surface with anisotropic characteristics |
| CN108469386A (en) * | 2018-03-22 | 2018-08-31 | 辽宁工程技术大学 | Method is determined based on the material of rock and soil feature of Mohr-Coulomb criterion of strength |
| CN109543326A (en) * | 2018-11-30 | 2019-03-29 | 浙江大学 | Open mine side slope rock mass discontinuity normal stress is classified the method for determination |
-
2019
- 2019-04-29 CN CN201910356014.XA patent/CN110044731B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1815184A (en) * | 2006-02-24 | 2006-08-09 | 浙江建设职业技术学院 | Non-homogenous structural shear-strength sampling method |
| CN201765075U (en) * | 2010-09-09 | 2011-03-16 | 中国长江三峡集团公司 | Measuring device capable of measuring partial stress state of shearing surface |
| CN203981499U (en) * | 2014-05-16 | 2014-12-03 | 山东科技大学 | The non-uniform charger of a kind of large scale coal body |
| CN105466790A (en) * | 2015-11-10 | 2016-04-06 | 内蒙古科技大学 | Evaluation method of shear strength of rock structural surface with anisotropic characteristics |
| CN108469386A (en) * | 2018-03-22 | 2018-08-31 | 辽宁工程技术大学 | Method is determined based on the material of rock and soil feature of Mohr-Coulomb criterion of strength |
| CN109543326A (en) * | 2018-11-30 | 2019-03-29 | 浙江大学 | Open mine side slope rock mass discontinuity normal stress is classified the method for determination |
Non-Patent Citations (4)
| Title |
|---|
| Non-linear Shear Strength Criterion for a Rock Joint with Consideration of Friction Variation;Hu Wang 等;《Geotechnical and geology engineering》;20180509;第36卷;第3731–3741页 * |
| REVIEW OF A NEW SHEAR-STRENGTH CRITERION FOR ROCK JOINTS;NICHOLAS BARTON;《Engineering Geology》;19731114;第287-332页 * |
| 基于非均布荷载的柔性基层沥青路面纵向开裂分析;叶亚丽 等;《长安大学学报（自然科学版）》;20190331;第39卷(第2期);第35-45页 * |
| 规则表面节理剪切力学行为研究;范祥 等;《武汉理工大学学报》;20170228;第39卷(第2期);第54-60页 * |
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